The recent announcement of Jodie Whittaker as the next star of Doctor Who has sparked a bit of controversy, but for the most part Whovians seem excited to meet a new version of the time-traveling alien. Now that the hubbub over the notion of the first female Doctor is dying down, the focus is turning to other important topics - chief among them: who will be there in the TARDIS with Whittaker as she travels the length and breadth of space and time.
We have one suggestion: It's time for Doctor Who to bring back Captain Jack Harkness.
On the off chance that you missed Jack's tenure on the show (or suffered a traumatic injury and somehow forgot him), here's a quick refresher. Played by Arrow's John Barrowman, Captain Jack is a time-traveler from the 51st century who first encountered the Doctor during the Blitz in World War II (in the two-part episode "The Empty Child"/"The Doctor Dances"). Originally acting as a con man, Jack accidentally releases a plague in London that the Doctor has to cure. Jack attempts to sacrifice himself to save others from a bomb, but the Doctor and Rose rescue him at the last moment and he travels with them for a while.
Jack became immortal after he was killed by a Dalek and Rose brought him back to life using the power of the Time Vortex. He was abandoned on a space station after the power left her, because her memory of the event was wiped. Obsessed with the Doctor, Jack found his way to Earth in the past and joined the covert organization Torchwood. Leading the Cardiff-based Torchwood Three, Jack used the team's location near a spacetime rift to keep an eye out for the Doctor. He left his Torchwood team to travel with the Doctor again, actually hitching a ride on the outside of the TARDIS, and eventually returned to Torchwood with a realization of how important the team is to him.
This doesn't mean that Jack has a happy ending with Torchwood Three, however. His brother, who had been kidnapped by aliens at a young age, returns and seeks vengeance against Jack for not rescuing him; he kills two members of Jack's team before he's finally defeated. He finds love, but through the course of their adventures also loses it in a heartbreaking way. His immortality is shown to be as much a curse as a blessing, and the most recent Torchwood series didn't exactly end with Jack being in the happiest place. Most of his team is dead, and his blessing/curse of immortality seems to have spread to someone else.
Jack and the Doctor
If there's one person in the universe that Jack respects, it's the Doctor. While he might have a few questions for her if they cross paths again (like where he/she was during the alien crisis of Torchwood: Children of Men or the events of Torchwood: Miracle Day), the Doctor could also heal Jack's world-weary grief in a way that no one else could. The Doctor could be someone who understands the weight of what Jack has seen and experienced, giving him a sense of perspective that he couldn't truly get from anyone who hasn't traveled across space and time and made decisions that affect millions of people. Traveling with the Doctor again and seeing how she handles the weight of it all could be just the catharsis that Jack needs to get past all of the pain and suffering the last two Torchwood series put him through.
Of course, the Doctor has experienced her own heartaches in recent seasons while she was played by Peter Capaldi. Losing companions, losing faith, and having to take the long way around could give her a new perspective on Captain Jack, who previously made the Doctor uncomfortable because he had essentially become a fixed point in time. Having a familiar face, especially one that isn't going to die at some point along the journey, could be a huge source of comfort for the Doctor, and could reinvigorate her in the same way that Rose restored Christopher Eccleston's Ninth Doctor after the events of the Time War.
Even if Jack and the Doctor only traveled together for a short while, that time could go a long way toward healing their grief and lightening the burdens that both of them carry.
Meeting the New Doctor
Of course, given the Doctor's new form, seeing her meet Captain Jack for the first time could be very entertaining. Being pansexual and a notorious flirt, Jack always seemed to have a soft spot for the Doctor's companions (and occasionally, for the Doctor himself). Perhaps the best way for them to meet up would be for Jack to not realize she was the Doctor at all; he might discover the TARDIS and know that the Doctor was around, and then meet her and think that she was either a random person or perhaps one of the Doctor's companions. This would give her an opportunity to mess with someone that she already knew a great deal about, and would set up Jack's conflicted feelings about her new form once the big reveal was made. This would likely be done for laughs, though, since the last thing we need is a Rose/Ten situation between Jack and the Doctor.
The big question would be where the two of them would meet. While Earth (and Cardiff specifically) seems like the most logical choice, given Jack's history as a Time Agent and the fact that he's immortal the two could meet up at pretty much any point in time and space. A meeting in the future could help to explain why Jack looks slightly older (though that could also be explained away by the time he spent as the only mortal in the world in Miracle Day), but even if they met in another time it's possible that Jack simply got ahold of a new vortex manipulator or other time travel device.
So, why would Jack be the best new companion for the Doctor? There are a few reasons. His appearance in the show could tie it back into the continuity of the pre-Moffat years, something that's been lacking a bit in recent seasons. It would also help to avoid the problem of whether the show should add a male companion simply to invert the usual male/female dynamic between Doctor and companion; it would be a male companion, yes, but one that was introduced years ago and has served in that capacity before.
Perhaps most importantly, it would also take stress off of the show and prevent the new season from seeming like a soft reboot of the series. There will be a new Doctor, a new showrunner and a new companion coming along all at once. Bringing back Jack Harkness would give audiences someone familiar and who is definitely part of the existing continuity, ensuring that the show doesn't seem too new.
Now all they have to do is make sure that John Barrowman has some free time for a little time travel.
Doctor Who returns in December with its annual Christmas special.